Crossover tube construction

ABSTRACT

A crossover tube construction includes a crossover tube on one flame tube with a flange on the outer end thereof cooperating with a flanged ring loosely mounted on the cooperating crossover tube on the adjacent flame tube with a ring overlying said flanges to hold them closely adjacent and permit relative transverse movement between adjacent flame tubes.

United States Patent [191 Morrison et a1.

[ 1March 20, 1973 CROSSOVER TUBE CONSTRUCTION [75] Inventors: Abraham Morrison, Windsor; Frederick C. Hetzer, Windsor, both of Conn.

[73] Assignee: United Aircraft Corporation, East Hartford, Conn.

[22] Filed: June 8, 1971 [21] Appl.No.: 151,019

[52] US. Cl ..60/39.32, 285/364 [51] Int. Cl ..F02c 7/20, F161 37/08 [58] Field of Search ..60/39.37, 39.32, 39.31;

[56] References Cited UNITED STATES PATENTS 3,344,601 10/1967 Mieczkowski ..60/39.32

1,974,780 9/1934 Mann ..285/364 3,479,069 1 1/1969 Sedan ..285/364 2,679,136 5/1954 Gaubetz ..60/39.32

Primary Examiner-Clarence R. Gordon Assistant Examiner-Warren Olsen Attorney-Charles A. Warren [5 7] ABSTRACT A crossover tube construction includes a crossover tube on one flame tube with a flange on the outer end thereof cooperating with a flanged ring loosely mounted on the cooperating crossover tube on the adjacent flame tube with a ring overlying said flanges to hold them closely adjacent and permit relative transverse movement between adjacent flame tubes.

2 Claims, 4 Drawing Figures CROSSOVER TUBE CONSTRUCTION SUMMARY OF THE INVENTION This invention relates to a crossover tube construction for interconnecting adjacent flame tubes in a combustion chamber construction in a gas turbine engine.

Small variations in alignment of the flamed tubes within the combustion chamber make difficult the proper interconnection of the crossover tube elements in assembly. One feature of the present invention is a crossover tube construction that permits adaptation to small misalignments in assembly. Another feature is such an arrangement of the crossover tube construction that minor relative movements may take place between adjacent flame tubes during operation of the engine without overloading the crossover tube construction.

One construction of this type is described in Mieczkowski U.S. Pat. No. 3,344,601. The present invention is in certain respects an improvement over this construction in that a greater freedom of movement is available with little possibility of binding of the relatively movable parts. In effect, the present invention permits a freedom of movement between the crossover tubes in all directions.

According to the present invention, the crossover tube on one of the flame tubes has a flanged outer end with a rebent peripheral edge. The cooperating erossover tube is cylindrical with a flanged ring loosely mounted thereon in abutting relation to the flanged end on the first crossover tube. The two flanged parts are held in the desired relationship with respect to each other by a U-shaped member straddling the two flanges and having a projecting tab secured to a cooperating tab on the first flange. The rebent peripheral edge on the flanged outer end on the first crossover tube is also straddled by the U-shaped member and serves to prevent binding of the flanged ring within the U-shaped member.

BRIEF DESCRIPTION OF THE DRAWINGS DETAILED DESCRIPTION OF THE INVENTION The invention is shown in a conventional semi-annular combustion chamber construction of the type disclosed, for example, in Savin U.S. Pat. No. 2,747,367. For the purpose of this invention, the combustion chamber is an annulus having an outer wall 2 and a concentric inner wall 4. Within this annulus are a plurality of parallely extending substantially cylindrical flame tube 6 having at their upstream ends an end cap 8 with one or more holes 10 for fuel nozzles not shown.

Adjacent flame tubes are interconnected laterally by crossover tube constructions which serve to balance the pressures within the tubes and to assure a transfer of the combustion in one tube to the adjacent tubes in starting the engine. As shown, one flame tube has a cylindrical crossover tube 12 thereon with a flange 14 on the end thereof. This flange has a bent over edge 16 over a portion of the periphery and also has a projecting tab 18 at another point in the periphery.

The adjacent flame tube has a cylindrical crossover tube 20 thereon, in substantial alignment with the tube 12. This crossover tube is surrounded by a loosely fitting ring 22 consisting of a cylindrical portion 24 and a disc-like'flange 26 at the outer end. This flange 26 engages flatwise against the flange 14 and is smaller in outer diameter than flange 14 so that its peripheral edge is within the bent over edge 16.

These two flanges 14 and 26 are held in close engagement with one another by a clamping member 28 that is U-shaped in plan view, FIG. 2, in order to be slidable over and to straddle the cooperating crossover tubes, as shown in FIGS. 2 and 3. This member 28 is also U-shaped in section as shown in FIGS. 3 and 4 so as to straddle the two flanges 14 and 26 to hold them substantially in contact with one another. The bent over edge 16 on flange 14 holds the U-shaped member in closely spaced relation to the flange 14 to assure that the flange 26 will be free to move laterally within the member 28 and also free to move to a small degree axially of the cross-over tube on which the ring 22 is mounted. To accomplish this, the bent over edge 16 is made slightly longer than the thickness of the flange 26 as shown.

This clamping member 28 has a projecting tab 30 thereon coextensive with the tab 18 and overlying said tab so that both tabs may be held together as by bolts I 32 extending therethrough. In this manner the clamping member 28 is held in the position shown surrounding the cooperating flanges l4 and 26. In order that the member 28 may straddle the projecting tab 18, the latter has a slot 34 therein as best shown in FIG. 3. It will be noted that the open end of the U-shaped member 28 extends in a downstream direction with the cooperating tabs 18 and 30 extending laterally of the gas flow.

The member 28 is preferably made up essentially of two pieces 36 and 3-8 which are welded together. The piece 36 is a flat piece resting against the flange l4 and having the tab 30 integral therewith. This piece has a U-shaped notch 40 therein which is larger in dimension than the crossover tube 12 that it straddles. The piece 38 is essentially flat but with a bent over peripheral edge 42 that engages with and is welded to the periphery of the piece 36 as shown. This piece 38 has a U-shaped notch 44 corresponding in shape to the notch 40 and also of such a dimension that it straddles freely over the ring 22.- The slot 34 is formed in the piece 38 as will be apparent. A third piece 46 is a flat tab welded across the U-shaped cross section adjacent to the tab 30 and serves to maintain the desired spacing between the pieces 36 and 38 and to damp any vibration between these two pieces.

It will be understood that the freedom of lateral and axial movement provided for the ring 22 within the clam ping member 28 provides for a slight misalignment between the cooperating crossover tubes during assemblyvand during the operation of the engine in which this construction is utilized, It has been found that this arrangement provides a substantially longer life for the arrangement shown since the parts of the crossover secured to a cooperating projecting tab on said cirtube construction are relieved of any compressive loadcular flange. ing as a result of thermal expansions and contractions 2. In a burner construction the combination with during engine operation and since any small misalignclosely spaced substantially parallel flame tubes, of ment is compensated for without any detrimental com- 5 a laterally projecting crossover tube on each of the pressive or tensile loading of the several parts. fl tubes Said tubes extending toward one we claim: another from the adjacent flame tubes and being in 1. In a burner construction the combination with Substantial alignment i one another closely Spaced substantially Parallelflame tubesiof a circular flange formed on the end of one of said a laterally projecting crossover tube on each of the tube extensions flame tubes, said tubes extending toward one another from the adjacent flame tubes and being in substantial alignment with one another,

a circular flange formed on the end of one of said tube extensions,

a ring having a cylindrical portion loosely surrounding the other tube and having an outwardly extending flange at one end thereof, said flanges overlying and in substantially parallel relation with one another, and

a retaining member U-shaped in cross section surrounding said flanges and overlying both flanges to hold them in closely adjacent relation, said retaining member having a projecting tab overlying and f a ring having a cylindrical portion loosely surrounding the other tube and having an outwardly extending flange at one end thereof, said circular flange being larger in diameter than said outwardly extending flange said flanges overlying and in substantially parallel relation with one another, and

a retaining member U-shaped in cross section surrounding said flanges and overlying both flanges to hold them in closely adjacent relation, said circular flange having a laterally extending rim deeper than the thickness of the outwardly extending flange. 

1. In a burner construction the combination with closely spaced substantially parallel flame tubes, of a laterally projecting crossover tube on each of the flame tubes, said tubes extending toward one another from the adjacent flame tubes and being in substantial alignment with one another, a circular flange formed on thE end of one of said tube extensions, a ring having a cylindrical portion loosely surrounding the other tube and having an outwardly extending flange at one end thereof, said flanges overlying and in substantially parallel relation with one another, and a retaining member U-shaped in cross section surrounding said flanges and overlying both flanges to hold them in closely adjacent relation, said retaining member having a projecting tab overlying and secured to a cooperating projecting tab on said circular flange.
 2. In a burner construction the combination with closely spaced substantially parallel flame tubes, of a laterally projecting crossover tube on each of the flame tubes, said tubes extending toward one another from the adjacent flame tubes and being in substantial alignment with one another, a circular flange formed on the end of one of said tube extensions, a ring having a cylindrical portion loosely surrounding the other tube and having an outwardly extending flange at one end thereof, said circular flange being larger in diameter than said outwardly extending flange said flanges overlying and in substantially parallel relation with one another, and a retaining member U-shaped in cross section surrounding said flanges and overlying both flanges to hold them in closely adjacent relation, said circular flange having a laterally extending rim deeper than the thickness of the outwardly extending flange. 